Figure 3.

FLAGToxR^CC undergoes DegS‐regulated proteolysis, which can be enhanced upon the overexpression of a synthetic C‐terminal OmpU fragment (YYF). Degradation assay was conducted with plasmid‐carrying cells grown in M9 maltose to mid‐log growth phase. Cultures were induced with IPTG for 1 h followed by inhibition of protein translation by Cm. Samples without chloramphenicol (Cm‐) served as negative controls. A. Proteolysis of anti‐sigma factor RseA is controlled by site‐1 protease DegS. Immunoblots utilizing anti‐FLAG antibodies show temporal stability levels of FLAGRseA in WT and degS background. B. Regulated proteolysis of FLAGToxR^CC is controlled by DegS. Immunoblots utilizing anti‐FLAG antibodies are showing temporal stability levels of FLAGToxR^CC in toxRS and toxRSdegS background. C. DegS‐PDZ activation by a synthetic C‐terminal OmpU fragment (YYF) induces an acceleration of FLAGToxR^CC degradation. Immunoblots utilizing α‐ToxR antiserum show chromosomal expressed levels of ToxR or FLAGToxR^CC. (•): Represents a nonspecific cross‐reacting background band.